MGW sight tool is a solid tool, well worth the money. Applying some heat for 10-15 minutes prior to removing sight helps a lot.
My first set, I had a gunsmith do them on a Shield, he bent 2 large brass punch before they moved.
Ok, first the Sport II does not have a thin barrel, the reason the plastic hand guard gets hot is S&W went cheap on the Sport II and did not use a heat shield under the plastic, easy correction by swapping to a set with heat shield.
A few hundred rounds a month will not wear out the barrel...
What will the 15T do that your Sport II can't?
Why not get an upper from someone else built the way you want? Or an entire rifle? Don't get me wrong, I love my Sport II, but many options out there.
DDM4(R)V7(R) Upper Receiver Group | Daniel Defense
LaRue Ultimate AR-15 Upper Kit...
Found nothing on the 2.0. Might have been an excuse, since they did not have what you asked for.
FYI S&W was sending out Free plugs for customers that could not find one without.
Recalls | Smith & Wesson
I just ordered 6 of the 17 round magazines, since the 15 round are pricey and/or out of stock.
Botach has free shipping $25 for 1, $22 for 3-5, $19.95 for 6+
https://www.botach.com/smith-wesson-m-p-pistol-magazines/